Nikolas Cruz, the suspected shooter in the mass shooting at Marjory Stoneman Douglas High School in Broward that killed 17 and left several more injured, is being charged with 17 counts of premeditated murder.

Cruz is being held without bond and has been kept separate from other inmates for his own safety. He is also required to wear a black suicide prevention vest, as authorities think he might be a suicide risk. Cruz is represented by an attorney from the Broward Public Defender’s Office.

According to the police report, Cruz, who is a former Stoneman Douglas student, arrived at the school in an Uber on Wednesday afternoon. He allegedly carried a black duffel bag and backpack containing a semi-automatic rifle and loaded magazines.

Cruz set off the school’s fire alarms to draw students out of classrooms before he began firing the rifle, according to details provided by police at a news conference on Thursday. He purportedly shot people inside five classrooms on the first and second floors of the freshman building before discarding the weapon, a vest, and ammunition in a stairwell.

Cruz got away by blending in with the fleeing students, sources say. He then allegedly walked to a nearby Walmart and bought a drink at a Subway. He also reportedly stopped at a McDonald’s. He was taken into custody without incident about an hour after the shooting in a residential neighborhood a mile away from the school. He reportedly had multiple loaded magazines in his possession.

Marjory Stoneman Douglas High School is one of the largest in the state, with about 3,000 students. Cruz’s actions caused the deaths of 14 students and three faculty members.

Gordon Weekes, the chief assistant public defender, told the press that the lawyers are still trying to piece together the details of Cruz’s life. Cruz’s defense team hasn’t seen his medical records yet, but he reportedly shows clear signs of some degree of autism and has long suffered from mental illness.

“We have a strong belief that his mental illness will be a significant issue in the case and is a significant issue in how we got to this point,” Weekes said. It is unclear whether Cruz’s attorney will pursue a mental health defense.

The teenager was reportedly troubled by the sudden death of his mother, Lynda Cruz, from pneumonia last November. After her death, Cruz and his younger brother went to live with a family friend in Palm Beach County, but the 19-year-old was purportedly not happy.

Cruz supposedly asked a friend he knew from Stoneman Douglas if he could move in with his family in northwest Broward. The friend’s family, the Sneads, agreed and Cruz has reportedly been living with them since Thanksgiving. The Sneads gave Cruz his own room and encouraged him to work toward his GED. Cruz also managed to get a job at a local Dollar Tree store.

Cruz legally bought the AR-15 rifle he used in the shooting. The Sneads never saw him use the gun, but they knew he owned one. It was kept in a locked gun cabinet, but Cruz reportedly had access to a key.

“The family is devastated, they didn’t see this coming. They took him in and it’s a classic case of no good deed goes unpunished,” Jim Lewis, the Sneads’ attorney, told the press. “He was a little quirky and he was depressed about his mom’s death, but who wouldn’t be?”

Weekes said state prosecutors will almost certainly seek the death penalty for Cruz after he is formally charged, but the decision could take weeks or months.